Design of Serial Server System Based on S3C44B0

In order to make the existing serial devices based on RS232, RS485 or CAN bus networked by Ethernet, the article introduces the design of a serial server system based on S3C44B0, elaborating the system hardware, software structure and working principle in detail . The actual application shows that the system realizes the data interaction between Ethernet and serial port, so that the existing serial device can quickly access the Ethernet.

introduction

At present, most of the automatic monitoring devices still use RS232, RS485 or CAN bus networking, which seriously affects the real-time, reliability and interactivity of the mine safety monitoring system. Industrial Ethernet has developed from 10 M and 100 M bandwidth to the current gigabit network, which has become the main networking method of mine monitoring systems.

Therefore, how to make the existing serial devices based on RS232, RS485 or CAN bus to operate in the form of Ethernet is a problem that needs to be solved at present. This article introduces a serial server system based on S3C44B0. This server system can convert serial data to TCP / IP protocol for data transmission and has a wide range of application prospects.

1 System hardware structure

The hardware structure of the serial server system based on S3C44B0 is shown in Figure 1.

Figure 1 The hardware structure of the serial server system based on S3C44B0

The main functions of the system: read data from serial devices, encapsulate the obtained data with TCP / IP protocol, send it to the host computer through the RJ 45 interface, and interact with the server program of the host computer; at the same time, send the host computer to The data of the serial port server is forwarded to the serial port, and then the serial port devices on the scene are remotely monitored through the network.

The RS232 interface circuit is shown in Figure 2. In this system, two independent serial ports are extended, which can communicate with three wires or communicate with Modem. The interface uses 2 MAX3232C chips, of which MAX3232C (1) is responsible for the level conversion of the serial port to send and receive signals, and MAX3232C (2) completes the level conversion of the handshake signal. The C10 ~ C15 of the processor S3C44B0 are used as nRTS1, nCTS1, TXD1, RXD1, nRTS0, nCTS0 signals, and PE1 and PE2 are used as TXD0 and RXD0 signals.

Figure 2 RS232 interface circuit diagram